Tread-forming press.



C. W, STEELE. TREAD FORMING PRESS. APPLICATION FILED MAYZT, 191s.

3 SHEETS-SHEET I.

WITNESS Pmtenwdl m. M1919.

0'. w. STEELE.

READ FORMING PRESS.

Patented Jan. 14, 1919.

3 SHEETSSHEET 2.

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fill-TAMLES W. S'llllillfllhlfil, UlEAltlitUl l', UHTU, ASSTGNUR TU TlElIlE lETlEtlE-STUNIIE TlllltE ttl l'lll lEt'UBlBlETt CUMPMY, UT .tllmtll l', UHTU, .tl. CURPURATTUN U-lli UHTU.

THEM-TURNING: PRESS.

.ttpplieation filed ltltay at, 191%.

To all whom it may concern:

Be it known that l, CHARLES W. STEELE, a citizen ot the United States, residing at rllrron, in the county of Summit, State ot Uhio, have invented certain new and usetul lmprovements in Tread-Forming Presses, ot which the tollowing is a specification.

This invention relates to vulcanizers tor articles manufactured ot rubber, and more particularly to apparatus tor molding or partially vulcanizing the tread strips ot pneumatic tire casings. lt has formerly been the practice to term these tread strips on drums provided with configuration'sinnlar to that on the finished tire carcass, trom a ring of uncured rubber which was subsequently tightly wrapped with cloths and then cured. W-hen cured and unwrapped, the tread band was turned inside out and placed on the unfinished or partially vulcanized tire casing and cured thereon.

lt is the purpose of this invention to construct a press in which these tread bands may be cured quicker and better than is now done.

Although l have shown one embodiment ot my invention in great detail, it is not necessary that the details be tollowed, as changes'may be made within the scope ot the invention.

l igure l is a vertical section through the press showing it open.

Fig. 2 is a plan view.

Fig. 3 is a horizontal section talren directly under the mold plate.

The press is mounted on legs or standard 1 supporting a table 2 in the central portion ot which is termed a cylinder 3 having a vertically reciprocating piston 4 designed to operate the parts ot the press. The piston rod 5 extends through a packing b in the lower part ot the cylinder and carries a cross-head or yoke 7,. the arms ot which carry vertical rods 8 carrying the platen TIOll'l the press. The rods pass through and are guided by bushings 9 on the upper surtace ot the table 2.

The platen is movable by the means described and is designated generally by the numeral 10 comprising a supporting plate ll mounted on the upper ends of the rods 8 and a circular steam chest 12 in which the steam tor vulcanizing is circulated, the steam chest being secured to the supporting plate 11 by bolts 13. Around the outside of specification of Letters Patent.

Patented slant llll llwllht.

Serial No. $336,700,

the steam chest 12 is placed a circular term, or mold, Ll, the outer surface ot which is cut to the shape desired tor a tread strip.

From the lower outside edge'ot the steam chest extend a series ot'radial brackets 15 having at their outer ends pivot pins l6 upon which are arranged to be mounted plates 17 which are curved in the arcs ot a circle concentric with the term and adapted when all brought together to inclose the article to be vulcanized and firmly press it to such an extent that it will be termed to correspond to the tread design.

Un the table 2 is mounted a ring 18 having termed therewith a series ot brackets T9 at the outer ends ot which are pivots 20 carrying the abutting members intended to close both plates together in a manner to be de scribed by the abutting plates and indicated by the numeral 21. They are in the torm ot right angle levers, one arm extending upward as at 22 and carrying a. roller 23 torming a rest for the pivoted plates 17 and hearing on the cam track Q-l tormed centrally on the outside ot its pivoted plate. The other arm ot the abutment is indicated at 25 and extends horizontally under the platen and over the top ot the table, the extreme end ot the arm being termed with shoulder 26 in the path ot the circular rib 27 termed on the underside ot the plate. lheat springs 28 are secured to the underside ot the arms 25 and bear against the top ot the table serving to maintain the abutments in the positions shown in Fig. la

The device is operated as tollows:

it suitable term. lt having been placed around the steam chest, a band ot uncured rubber is placed around the torm and tluid under pressure applied to the upper part ot the cylinder 3 through the pipe 29,-and the piston. is torced downward in the cylinder drawing the platen with the term between the abutments. The rollers 23 riding on the cam tracks 24- bring the plates it? together around the rubber. its the plates reach the lower limit ot their movement, the shoulders 26 are contacted by the rib 2i? and the plates are given a final squeeze which serves to torce the rubber into the cavities on the term. @team being admitted to the steam chest, the press remains in the closed position until the tread band is cured, when it is opened up by a reverse movement of the piston and the tread band removed.

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lllll While I have shown plates 17 as solid, it may be preferable to hollow these out and provide additional steam connections for curing the outside of the tread bands. Other modifications may suggest themselves to those skilled in the art and it is not my intention to be confined to the design shown herein.

I claim:

1. In a press for vulcanizing, the combination of a circular form upon which the unvulcanized article is placed, a series of plates in the arcs of a circle pivotally mounted adj acent the form, means to rock the plates on their pivots to form a complete circle around the article and to press the plates together, to exert curing pressure thereon.

2. In a press for vulcanizing, the combination of a circular form upon which the unvulcanized article is placed, a series of pivots arranged about and below the form, plates in arcs of a circle mounted to rock on the pivots, the upper faces of the plates when in their lower-most position lying below the form, means to rock the plates upwardly to form a complete circle about the form and to press the plates together to exert curing pressure on the article.

3. In a press for vulcanizing, the combination of a circular platen, a form on said platen, a series of plates in the arcs of a circle pivotally mounted adjacent the form, a series of abutments located around the forms and adapted to contact the plates, means to" cle pivotally mounted adjacent the form, a

series of abutments located around the forms and adapted to contact the plates, means to cause relative movement between the platen and the abutments to rock the plates on their pivots to form a complete circle about the form, and means to give the plates an increment of pressure at the point of closing.

5. In a press for vulcanizing, the combination of a circular platen, a form on said platen, a series of plates in the arcs of a circle pivotally mounted adjacent the form and carried by the platen, a series of abutments contacting the plates and relatively stationary thereto, and means for moving the platen between the abutments.

6. In a press for vulcanizing, the combination of a-circular platen, a form on said platen, a series of plates in the arcs of a circle pivotally mounted acent the form and carried by the platen, a table ,below the platen, a series of abutments contacting the plates, pivotal mounting for said abutments on the table, means for moving the platen between the abutments, and additional means for rocking the abutments atthe limit of movement of the platen to give the plates an increment of pressure at the point of closing.

7. In a press for vulcanizing, the combination of a-circular platen, a form on said platen, a series of plates in the arcs of a circle pivotally mounted adjacent the form and carried by the platen, a table below the platen, a series of abutments pivoted on the table, means for moving the platen between the abutments, an arm on each said abutment contacting one of said plates, :1 second arm on said abutment projecting beneath the platen and adapted to be rocked by it at the limit of its downward movement.

CHARLES W. STEELE. 

